Conference call circuit using reversible analog to digital converter

US4162376A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Peter Hirschmann · Puchheim, DE
• Ernst Hoefer · Munich, DE

Key dates

• Filing date: Jul 21, 1978
• Grant date: Jul 24, 1979
• Expiry date: Jul 21, 1998

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04M3/561
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

A circuit arrangement is disclosed for individual subscribers in a telecommunication set up. The circuit arrangement converts analog signals into digital signals and digital signals into analog signals. When operated in a conference connection, summation signals are received by a subscriber which contain the subscriber's own share. Output digital signals from the subscriber are stored and converted into an analog value and are then subtracted from the received summation signal converted into an analog value.